Injectable corticosteroid and local anesthetic preparations: a review for radiologists

Radiological interventions for soft tissue injuries in sport

Injection therapy has played an integral role in the rehabilitation of sports injuries for many years. The athlete's primary goal is a rapid return to sporting activity. This may be achieved by a combination of either a temporary or permanent reduction in pain, and by a pharmacological or physiological effect that promotes or accelerates a healing response. A wide variety of pharmacological agents are used. However, there is often a lack of good evidence that quantifiable effects can be achieved. There are restrictions on the use of some pharmaceutical agents. This article reviews the various pharmacological agents and bioactive substrates that are available, and discusses the current evidence base of their use in common sports injuries.

Corticosteroids and local anesthetics decrease positive effects of platelet-rich plasma: an in vitro study on human tendon cells

PURPOSE

To determine the effects of mixing anesthetics or corticosteroids with platelet-rich plasma (PRP) on human tenocytes in vitro.

METHODS

Two separate protocols (double spin and single spin) were used to obtain homologous PRP from the blood of 8 healthy volunteers. Discarded tendon acquired during biceps tenodesis served as tendon specimens for all experiments. After cell isolation, tenocytes were treated in culture with PRP alone or in combination with corticosteroids and/or anesthetics. Fetal bovine serum in concentrations of 2% and 10% served as controls. Cell exposure times of 5, 10, and 30 minutes were used. Radioactive thymidine and luminescence assays were obtained to examine cell proliferation and viability.

RESULTS

The presence of lidocaine, bupivacaine, or methylprednisolone resulted in significantly less proliferation than the negative 2% fetal bovine serum control (P < .05). When we compared groups, both lidocaine and bupivacaine had a greater inhibitory effect than methylprednisolone (P < .05). At all time points, viability was significantly decreased in the presence of lidocaine, bupivacaine, or methylprednisolone compared with the negative control (P < .05).

CONCLUSIONS

The addition of either anesthetics or corticosteroids to PRP resulted in statistically significant decreases in tenocyte proliferation and cell viability. These results suggest that incorporation of anesthetics or corticosteroids, either alone or in combination, with PRP injection may compromise the potentially beneficial in vitro effects of isolated PRP on tendon cells and compromise cell viability at the site of tendon injury.

CLINICAL RELEVANCE

Anesthetics or corticosteroids either alone or in combination should be used carefully to preserve the proposed positive effects of PRP in the treatment of tendon injury.

Intrasomatic injection of corticosteroid followed by vertebroplasty increases early pain relief rather than vertebroplasty alone in vertebral bone neoplasms: preliminary experience

PURPOSE

In this prospective multicenter study, we evaluate the effectiveness of corticosteroid plus vertebroplasty rather than vertebroplasty alone in the analgesic treatment of single-level vertebral neoplasms or pathological fractures.

MATERIALS AND METHODS

From January 2009 to February 2011, we prospectively enrolled 20 consecutive patients (11 women, nine men; age range 46-78 years; mean age 65.1 years) with single-level vertebral neoplasm or pathological fractures totally or partially refractory to analgesic treatment, with indication to vertebroplasty. Institutional review board approval and informed consent were obtained. The inclusion criteria for the study were the presence of a single-level pathological fracture not extended to the posterior wall or symptomatic localization of primary or secondary neoplasms, visual analogue score (VAS) ≥5, and life expectancy more than 3 months. Exclusion criteria where all contraindications either to corticosteroid injection included allergy (local sepsis, bacteremia, allergy) or vertebroplasty included coagulopathy, etc. The population was randomly divided into two groups: in group A, patients underwent intrasomatic injections of 4 mg/ml of dexamethasone phosphate followed by a cement injection; patients in group B underwent standard vertebroplasty. VAS score was evaluated and compared between both groups of patients at 6 h, 24 h, 48 h, 7 days, 30 days, and 3 months after the intervention plus last available follow-up. Statistical analyses were performed by application of the t test.

RESULTS

Technical success was achieved in all cases. In group A, we treated six male and six female patients (age range 46-73 years, average 60.2 years). Pre-intervention VAS in group A ranged between 7 and 10 points, average 8 points. In group B, we treated three male and five female patients (age range 52-78 years, average 67.3 years). Pre-intervention VAS score in group B ranged between 7 and 9 points, with an average 8 points. Patients in group A in respect to patients in group B had a higher reduction in VAS, with a difference of 25.4% (VAS reduction average 5.5 versus 4.1) at 6 h post-intervention, 24.5% (VAS average 5.7 versus 4.3) at 24 h, 25% (VAS average 6 versus 4.5) at 48 h, 23% (VAS average 6.5 versus 5) at 7 days, 16.4% (VAS average 6.7 versus 5.6) at 30 days, 8.9% (VAS average 6.7 versus 6, .1) at 3 months. The last available follow-up ranged from 3 to 24 months in group A and from 5 to 20 months in group B.

CONCLUSIONS

In our preliminary experience, pre-vertebroplasty injection of intrasomatic corticosteroid in comparison to vertebroplasty alone is able to increase the early pain relief of the procedure.

Temporomandibular joint injection with corticosteroid and local anesthetic for limited mouth opening

It is unclear whether temporomandibular joint (TMJ) injections with local anesthetic and corticosteroid are an effective first-line management modality for patients with limited mouth opening. The purpose of this study was to determine the effectiveness of TMJ injections in patients with disc displacement without reduction (DDWOR), i.e. closed lock, at the University of Southern California Orofacial Pain and Oral Medicine Center. A retrospective chart review was conducted using a database of over 4000 patient records from 2003-2010. We identified 17 patients (16 female; 1 male) between the ages of 16 and 70 years who had been diagnosed with DDWOR and received a TMJ injection. Active mouth opening before injection ranged between 15 and 40 mm (average 29 mm), and active mouth opening after injection and manual mobilization ranged between 25 and 50 mm (average 39 mm). The average increase in mouth opening after injection and manual mobilization was 10 mm (P = 0.0004). TMJ injection with corticosteroid and local anesthetic is suitable as an alternative first-line management modality for DDWOR.

Injectable corticosteroid preparations: an embolic risk assessment by static and dynamic microscopic analysis

BACKGROUND AND PURPOSE

Transforaminal CS injections have been associated with severe adverse CNS events, including brain and spinal cord infarction. Our purpose was to describe the static and dynamic microscopic appearances of CS preparations, with an emphasis on their potential to cause adverse central nervous system events by embolic mechanisms during transforaminal injection.

MATERIALS AND METHODS

Pharmaceutical preparations of nondilute injectable CSs were used after appropriate mixing: MPA (40 mg/mL), TA (40 mg/mL), and DSP (8 mg/2 mL). For dynamic imaging, a novel methodology was devised to replicate the flow of crystals within spinal cord arterioles. In addition, CS preparations were mixed with plasma to assess for changes in crystal size, morphology, and tendency to aggregate.

RESULTS

The CS preparations MPA and TA are composed of crystals of varying sizes. MPA crystal size range was 0.4-26 μm (mean, 6.94 μm), TA crystal size range 0.5-110 μm (mean, 17.4 μm), and DSP did not contain any significant crystals or particles. There was no change in the crystal morphology or propensity to aggregate after mixing with local anesthetic. After mixing with plasma, the crystals also were unchanged; however, there was a significant reduction in the size of aggregates. On dynamic imaging, these aggregates were proved to maintain their integrity and to act as potential embolization agents.

CONCLUSIONS

MPA and TA have a substantial risk of causing infarction by embolization if inadvertently injected intra-arterially at the time of TFESI. DSP is completely soluble and microscopically has no potential to obstruct arterioles. When performing cervical TFESI procedures, the administration of insoluble CSs should be avoided.

Adverse events from diagnostic and therapeutic joint injections: a literature review

This review article classifies the various adverse reactions arising from intra-articular injections by severity, diagnostic category, and whether they are due to corticosteroid, local anesthetic or viscosupplementation injections. Life-threatening and serious adverse events from intra-articular injections are rare and range from local complications to systemic afflictions. Measures to reduce the likelihood of an adverse event occurring are outlined and patients with significant features in their clinical histories, predisposing them to adverse events, are highlighted.